Why do golf balls – those things in the picture – have all those little dents? It turns out golf balls, which you hit with a club, fly faster through the air because they’re covered with round dimples. So of course someone had to ask, what if we put little dimples all over a car? Would the car use up less fuel pushing against the air? Adam Savage and Jamie Hyneman at Mythbusters tested 3 Ford Taurus cars: one normal car, one car covered in smooth clay, and one covered in clay with 1,082 dimples scooped out. Sure enough, while the smooth cars could drive 26 miles on a gallon of gas, the dimpled car drove almost 30 miles! On a long trip that saves a lot of gas, if you’re okay with driving a funny-looking car.
Wee ones: What shape is a golf ball?
Little kids: Golf balls don’t all have the same numbers of dimples. Which has more, a ball with 20 dimples or a ball with 30 dimples? Bonus: If the dimpled car could drive 30 miles on a gallon of gas while the regular car drove only 26 miles, how much farther could the dimpled car drive?
Big kids: If you helped smash the dimples into Adam and Jamie’s test car, and you can smash 10 dimples each minute, about how long would it take you to make the 1,082 dimples? Bonus: If your car tank holds 20 gallons of gas, and you’ll drive 4 miles farther on each gallon after banging up your car, how many more miles do you get out of every tank of gas?
Wee ones: A circle, or if you’re talking about 3-D (chunky) shapes, it’s a “sphere.”
Little kids: The 30-dimple ball. Bonus: 4 miles farther.
Big kids: 108 minutes. Bonus: 80 more miles!
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.